Wing lift control for aircraft



Marh 23, 1948.

E. A. STALKER WING LIFT CONTROL FOR AIRCRAFT Filed 001'.- 13, 1943 3 Sheets$heet 1 ATTORNEYS March 23, 1948! E. A. STALKER WING LIFT CONTROL FOR AIRCRAFT 3 Sheets-Sheet 2 Filed Oct. 15, 1943 wdl .w mm a v vm v INVENTO a l v I fgwm waab ATTORN FIYS I v March 23, 1948. E. A. STALKER WING LIFT CONTROL FOR AIRCRAFT 3 Sheets-Sheet 3 Filed Oct. 13, 1943 Patented Mar. 23., 1948 UNITED STATES ATE-NT OFFICE WING LIFT CONTROL FOR AIRCRAFT Edward A. Stalker, Bay City, Mich. 7

Application October 13, 1943, Serial No. 506,019

I 4 Claims.

This invention relates to aircraft and more particularly to the control of the lift of a wing.

It is the principal object of the invention to provide an aircraft having a wing slot and a blower for inducing a flow through the slot for increasing the lift of the wing when taking off and when coming in for a landing and in which in response to the landing of the plane the slot flow is reduced or terminated .to thereupon decrease the lift.

It is a further object to provide such control of the lift of, the wing which takes place in response to actual flight conditions and does not require the detailed attention of the pilotbut in which the pilot may exercise a supervisory control when desired.

I accomplish the objects of the invention by the means illustrated in the accompanying drawings in which- Fig. 1 is a front elevational view of the aircraft;

Fig. 2 is a fragmentary side view of the aircraft partly in section;

Fig. 3 is a detail sectional view of a control valve;

Fig. 4 is a fragmentary side elevation of the blower partly in section;

Fig. 5 is a vertical axial section of the blower hub;

Fig. 6 is a horizontal section of the blower hub;

Fig. '7 is a side elevation of a modified form of aircraft shown partly in section;

Fig. 8 is a side elevation partly in section of an aircraft adapted for arrested landings; and

Fig. 9 is a fragmentary plan view of the aircraft of Fig. 8.

Even the simplest aircraft is relatively too complicated for use by persons outside a small category and if it is to have wider use its lifting capacity for landing must be increased, and if its high speed is to be sufiiciently large the landing gear must b retractable.

This invention described means of relieving the operator of the aircraft of the necessity of initiating the operation of each of the lift augmenting and landing gear devices. Thus the operator is relieved of the need to remember an involved sequence of, operations to be performed, and is also divested of the demand for quickness in certain emergencies, a quickness which the majority of persons would not possess or could not attain without a long training.

In Fig. 1 is shown a fuselage I supported in the air by the wing 2 equipped with an adjustable flap 2a. Tail booms 3 support the tail group. The machine is supported on the ground by the landing gear 4. The engine is 5 and the propeller is S, the plane for purposes of illustration being shown as the pusher type.

In my U. S. Patent No. 1,913,644 I have shown how the lifting'capacity of wings can be increased by a blower driven by the propeller operating as a windmill, an arrangement of this type being preferably utilized in the present case. The blower l is located within the wing 2 substantially centrally thereof and is driven b the shafts 8 and 9 operably connected to the engine 5 and the propeller 6. An automatic clutch I0 is provided between the engine and the propeller for disconnecting the engine so that the propeller can drive the blower relieved of the torque of a dead engine.

When the airplane is to be landed the flap 2a is depressed and the engine is throttled. The automatic clutch It then frees the engine from the propeller permitting it to act as a windmill to drive the blower i which inducts the boundary layer through the slot II in the wing located adjacent the end of the wing main body and discharges it through the slot [2 located adjacent the nose of the wing. The wing is then able to develop a high lift coefiicient.

When the airplane makes contact with the ground it is desirable to destroy or materially, reduce the high lift coeihcient so that the Weight will be transferred to the wheels. They are equipped with brakes and at low speeds are the most effective means of stopping the aircraft. The lift is reduced by interrupting the pumping action of the blower i. This is accomplished automatically by the relative movement of the landing gear parts.

In Fig. 1 the wheel l3 moves upward upon contact with the ground so that the strut 14 moves relative to the strut Hi. This relative movement actuates the bell crank it by means of the articulated rod I1. The movement is transferred by the bell crank l8 and rod l9 to the lever 20 of the valve 2! which directs oil under pressure from the pressure line Zia to the cylinder 22 by way of tube 23. The piston 24 within the cylinder reduces the pitch of the blower by means of the rack 25 and pinion 26 which controls the pulley 21 and belt 28. The blades la of the blower are supported for rotational movement and for pitch adjusting movement in the hub 33 which is driven by a hollow shaft 39, preferably integral with the hub, and rotatably supported in bearing M. A drive gear 38 fixed to the hollow shaft meshes witha corresponding drive gear on shaft 8, to

3 provide for rotation of the shaft 39 and the hub assembly from the engine, or from the propeller when windmilling, as described above.

Each blade Ia has a crank arm lb which is connected by arms 32 with a spider 31. The spider is supported at the upper end of a rod 34 so that in response to axial movement of the rod, and through the ball and socket connections to the crank.arms,. the blades are simultaneously turned in the hub, and their pitch thus adjusted.

In order to efiect the vertical travel of the rod 35 it is provided at its lower end with a ball bearing 35 which is received within threaded sleeve 36 having a spline connection withthe stationary mounting support to provide. for. axial.

travelthereof while restricting the same against rotation. Such axial movemanikis produced .as

a result of the rotation of nut 35, the outer periphery of which receives the belt 28. Thus in response to travel of rack 25 and pulley 2'1 the rod fi lis raised orlorweredresulting in vcorre sponding adjustment of the. pitch'of the blades during continuous rotation-of the hub 33.

When the airplane is taking off, as soon as the wheel l3 leaves the ground the rod iii is loweredand the valve leverdfi. isthen rotated downward, under the. action .of spring a to a predetermined position, providing for thessetting of the valve to the positiontosupply pressure fluid to wtheupiston such direction as to effect ncreasegin the pitchnofthe' blade. Control of the blade pitch during flight is under the-con trol of the pilot who. .can .actuaterthe valvezi through the 'setting-oflhandslever 29 which is connectedlto va1ve..2l by means of rod Bil. This lever isffricti'onally restrained against -movement but maybe reset under the actionof the landing earas aboveidescri-bed upon landing so -that the actuation ofrod IE will change the setting civalve'leverifi to controlthe functioning-of the, device I in accordance with-actual flight-conditions. a

.Preferably rod1l9 has akneejoint iilb in-the formof a toggle which is-normallydsept closed by means of a spring lea. With the toggleclosed the, rod Hi can exert an upward push upon a valve lever 26. In case-the pilot wishes to change the setting of the valveiwhenthe rod I9-is up, 113502 11 break .the toggle .joint by" forward movement of 1 lever .29 which through rod 39a engages the knee. joint .to break the toggle, overcoming the action-of. spring I So, thereby -permittingmanualcont olof va ve-:2 1

Thevalve -2 l as ;shown in J-Figures 2 and 3 receivesoil.undenpressure. from the tube 2 la leading from a. suitable source ofapressuresuch asa pump. As shown in Figure 3 thevalve is in-positionfor the pressure tofiow. to tube=23 to the rear end of cylinder 522 to reduce the pitch of the blowers. V The fluid .from the frontend- 0f-22 es ap h ou h; tube 33 into discharge tube 3311 by which it is returned to areservoir not shown,

When the valve is'sreadjusted to deliverpressure to tube. .33 the. passage 2 lb registers with tubes Zia and 33. Fluid atthe rearendof "2- 2 escapes through tube .23 .into passage 22c and 4 the pilot, assurance is provided that the most desirable conditions will be 'maintained at all times as required for the particular conditions of grounirclosing. acircuitfrom. the battery 43 (or generator id) to the motor i which turns the gears 46 and dLthe latter being fixed to the shaft :38 carrying the pulley 21 for changing the 'blower pitch as described above.

.dwitfihifi ijstqpslthe motor when the pitch has The limit reached apreassigned value in either direction. In addition to the switches 42 and 69 there is a masterswitch-fifl operated by a remotecontrol 5! located conveniently for actuation by the pilot. Thus after the limit switch has stopped the motor it can still be reversed so as to increase the p i fih- .Z'I 9 0i accomplishes thisiby the. remote switch control 1 5 I ,aacting; 0n: the master switchrifi;

It is also, possible to.g-locate':theimaster. switch within reach: of the pilot-so: the. hermay operateit d y i reasenthe pitchwh n t e rplan ta es. z-ofli: "and .the Wheel-H 3 drops the switch is reversed jtoqthetpositionsfor increasing the blower-pitch.rgTheniwhen :the:

wheel again makes contact with thigroundcthe switch is moved to the position fonrreducin'g the pitchoftheblower. Y i

still ther .iormiofrztrheinvention. is shown'in Fig 8 and 9 Whi nshows the cables-. 52 eof an arresting device such; as. is -;used ion s'ship.;.bo.ard;.

The hook 53 engages the cablesi52-and also closes the inlet to vtlleiblowerfiil @which Iis'sho'wn 'asa centrifugal type :with'inlet; at the? topi- The plate 55 serves to close the blower inlet mascot/n position which itwould ocupywhn the hpok is moved rearward. The latters motion is trans ferred. .to the plate .55 by the rodsifiahdET-and the bell cranks 58 and 59; s'pring 53d nQr-ma-lly projecting the hook andholding the plate in its raised position.

The blower ordinarily inducts slot 60 in the wing flap 6i.

The blower is driven either -by" th e enginergr. the propeller, preferably through an automatic clutch 62 as described'above. V

While the forms of apparatus hereindescribed constitute preferred embodiments,'oi-ltheuinvene tion, it is to bennderstoodthatthe jnventionds not limited to these precise iormsoi apparatus, and that changes-maybe'madegfiheiiein without ,departingfrom the-scope of the inventiorrwliich Wing including a blower in e'omm unication; with the wing interior-to induce ajflpwthrou hlsaid sl t. r adilycontrol-lable m e is fnr. reducing the flow induced i d "blo\ver;th1:ough- .saidslot.

and means 'responsive'to .thejjoperation..of=.said

landing gear uporr the landinggofthe aircraft .for actuating saidflow reducin .meansltoreduce,the flow through-said, slot.

In comb n nan aircraft. Lemaitre an arresting device fgr';lanjding, arhollowswing having a slot in itssuriacfl leading into the win interior; atblo wer within the... aircraft in communication with said interior to induce a fiow it through rod ll theiblower :1." The switch. is; a reversin :switchsoethat:

through said slot to augment the lift of the wing, means for readily controlling the flow induced by said blower, and means responsive to the action of said arresting device in landing for actuating said flow controlling means to reduce the flow of pumped air through said blower.

3. In combination in an aincraft equipped with landing gear, a hollow wing having a slot in its surface leading into the wing interior, a blower within the aircraft in communication with said interior to induce a flow through said slot to augment the lift of the wing, said blower having blades of adjustable pitch, means for adjusting the pitch of said blades, and means responsive to the operation of said landing gear in landing for actuating said adjustable means to effect rapid reduction of the pitch of said blades.

4. In combination in an aircraft having landing gear, a wing having a slot in its surface leading into the wing interior, means for increasing the lifting capacity of the wing including a blower for inducing a flow through said slot, means for rapidly controlling the flow induced by said blower, means responsive to the operation of said landing gear upon the landing of the aircraft for actuating said flow controlling means 6 to rapidly reduce the flow through said slot, and means responsive to the operation of said landing gear in taking ofi for actuating said flow controlling means to rapidly restore the flow through said slot.

EDWARD A. STALKER.

REFERENCES CITED The following references are of record in the 

